1. Field of the Disclosed Embodiments
This disclosure relates to systems and methods for implementing real-time or near-real time tracking and display of a plurality of vehicles operating in an area, particularly using low cost line-of-sight communication devices operating as cooperating data transmission and relay nodes in a MESH network topology.
2. Related Art
Conventionally, there are multiple “airport centric” tracking requirements that exist to track vehicles operating in modern airport environments. At a high level, these tracking requirements include a number of individually-identifiable systems and system related functions based on the uses of individual vehicles and the areas on the airport property in which the individual vehicles are permitted to operate, among other considerations.
A first and critical level of vehicle tracking is provided for those vehicles that require that their locations be continuously monitored in operation and integrated into air traffic control (ATC) separation schemes for display, for example, on ground situational awareness displays. Based on the complexity involved in maintaining the situational awareness display and costs involved in critical tracking of these vehicles, a number of vehicles that are afforded this level of tracing is very carefully controlled. Safety of operations in and around aircraft justifies the expense in the case of these vehicles. This highest level tracking and display integration scheme is reserved for only certain ground vehicles that interact with active aircraft in areas where aircraft maneuver on runways and/or taxiways, for example. The positions of these vehicles are typically, of necessity displayed on a common situational awareness display to attempt to ensure controlled separation of vehicles and aircraft.
There are various, comparatively very expensive, technologies deployed to accomplish ground tracking of the runway- and taxiway-accessible vehicles. These technologies include the following. Airport Surface Detection Equipment, Model X (ASDE-X) is a system that enables air traffic controllers to detect potential runway conflicts by providing detailed coverage and display of movement of aircraft and certain vehicles on runways and taxiways. ASDE-X collects data from a variety of sources to track vehicles and aircraft on the airport movement area and obtain identification information from aircraft transponders. Surface Movement Guidance Control System (SMGCS) provides guidance to and control of aircraft, ground vehicles, and personnel on the movement area of an airport. Guidance relates to facilities, information, and advice necessary for pilots of aircraft or drivers of ground vehicles to navigate the movement area and to keep aircraft or vehicles on the surfaces or within the areas intended for their use. Control of the aircraft and vehicles involves a system of measures undertaken to prevent collisions and ensure traffic flows safely on the critical portions of the airport. Automatic Dependent Surveillance—Broadcast (ADS-B) provides a cooperative surveillance technology in which aircraft and vehicles equipped with ADS-B transceivers determine and broadcast their positions to compatible transceivers enabling the aircraft and/or vehicles to be tracked. The tracking information can be received and displayed by ATC ground stations to provide situational awareness and allow safe separation among participating aircraft and vehicles.
A second and comparatively less expensive system of tracking vehicles may be provided for airport service provider ramp vehicles. This level of tracking may be afforded to vehicles that do not operate on runway or taxi areas of the airport. The tracking of these vehicles may be limited to schemes that manage the vehicles by less stridently tracking locations and speeds of the vehicles in order to monitor safe operation of the vehicles and to ensure that the vehicles remain within their prescribed geographic boundaries (geo-fence). Locations of these ground assets are not displayed on ATC displays and they have no ATC services supplied to them.
Schemes also exist for what could be considered asset tracking on the airport. Containers, pallet and/or container unit load devices (ULDs), luggage carriers and buggies, and the like can be located on the airport grounds. Typically, low-cost active RFID-type technologies (e.g., less than $50 per asset) are provided. Per unit costs of such trackers are limited because some airports could have more 10,000 trackable containers/ULDs.
High availability “low cost” tracking systems are simply not conventionally available, leaving a large contingent of potential customers without a solution for their vehicle and asset tracking needs, particularly in real-time or near real-time. Basically, the only options available in today's airport environment for monitoring and tracking assets are based on the following technologies. Each having attributes that drive their costs up. As a first example, conventional ADS-B squitters cost in excess of $3,000 each. These components are those generally required for use on those vehicles operating in the aircraft movement areas noted above, necessitating certified avionics quality devices, which greatly increase their cost. As a second example, conventional vehicle tracking systems using any one of GSM, GPRS, 3G phone technology or the like to report positions carry with them recurring monthly costs of phone-type service that may be as much as a particular vehicle operator may be expected to be willing to pay for a complete system. As a third example, licensed VHF frequency band vehicle tracking systems necessitate the use of certified and qualified high power output devices. This hardware typically costs more than $600 per vehicle, still a potentially prohibitively high cost for equipping an entire fleet of vehicles.